controlling connection - PPP

This is a discussion on controlling connection - PPP ; Hi,
Is there a way to enforce stopping linux ppp connection after a fixed
time period as my idle time disconnect parameter is being defeated by
port scanning....
Thanks
Berni Elbourn...

Re: controlling connection

Did you try this? When giving the 'outbound' expression to tcpdump it
gives:
tcpdump: inbound/outbound not supported on linktype 113

When looking into the source this is caused by the fact libpcap does
uses a PF_PACKET socket on linux which does not provide a in-/outbound
notification inside of the packet data and BPF only able to act on the
packet data not on data supplied out-of-band.

Re: controlling connection

Hi Clifford,

you wrote:
> > When looking into the source this is caused by the fact libpcap does
> > uses a PF_PACKET socket on linux which does not provide a in-/outbound
> > notification inside of the packet data and BPF only able to act on the
> > packet data not on data supplied out-of-band.
>
> Interesting, I just supposed that tcpdump itself omitted that support.
> Also pppd 2.4.1 and 2.4.2b3 seem to use libpcap. ?

I looked into it now. Yes, pppd does use libpcap. But not its functions
to snoop the packets since it does get them anyway. So pppd can
circumvent the problem caused by using the PF_PACKET socket.